USS Saint Louis, a 9700-ton cruiser built at Philadelphia, Pennsylvania, was commissioned in August 1906. After a brief period in the Atlantic, she was assigned to the Pacific Fleet, arriving there in mid-1907. For the next decade, Saint Louis served as a training, receiving and submarine support ship, as well as in traditional cruiser roles along the U.S. west Coast, at Pearl Harbor and elsewhere in the eastern Pacific.
In 1917, with the U.S. entry into World War I, Saint Louis was transferred to the Atlantic, where she served as a transport and escorted convoys. Following the Armistice, she brought home thousands of U.S. troops from Europe. Redesignated CA-18 in July 1920, she was sent to the Mediterranean during a period of great turmoil in Turkey. Returning to the United States late in 1921, Saint Louis decommissioned in March 1922. After eight years in reserve, she was sold for scrapping in August 1930.
